Selective signaling system



J. C. FIELD.

SELECTIVE SIGNALING SYSTEM.

APPLICATION FILED APR'.24, I917.

Patented May 24, 1921.

UNITED STATES PA ENT OFFICE.

JOSEPH C. FIELD, OF ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COM-,

PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SELECTIVE SIGNALING SYSTEM. v

Specification of Letters Patent.

Patented May 24, 1921.

Original application filed May 18, 1916, Serial No. 98,384. Divided and this application filed April 24,

/ 1917. Serial No. 164,247.

To all whom it may concern:

Be it known that I, JOSEPH C. FIELD, a citizen of the United States, residing at Oran e,'in the county of Essex and State of New ersey, have invented certain new and\ useful Improvements in Selective Signaling Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to selective signaling systems, and is a division of application, Serial No. 98384 filed May 18, 1916, which issued as Patent No. 1,343,256, June 15, 1920.

It is the object of this invention to provide a new and improved selective signaling systerm.

In accordance with one feature of this invention, there is provided a selective signaling system in which there may be'a very large number of individual stations, the responsive device at each of which is selectively responsive to a definite combination of current impulses.

In accordance with another feature of this invention, there is rovided a selective signaling system havlng a plurality of waystations, in which each station may be called individually, in groups or all at the same time.

In accordance with another feature of this invention, there is provided a selective signalin system in which a waystation may be selectively called and all waystation selectors may be advanced to a predetermined position, after which each impulse impressed upon an-extraneous circuit associated with the selective signaling system causes the advancement of all selectors to momentarily operate signaling devices controlled thereby.

This invention will be more fully understood from a consideration of the following description, taken in connection with the accompanying drawings wherein Figure 1 shows a selective signaling'system illustrating one embodiment of this invention; Fig. 2 is a side view of a section of the step-by-step element of a selector showing an elongated holding pin employed when time signals are being received at the way stations of the system; Fig. 3 is a bottom view of the same section of the step-by-step element showing the manner in which the elongated holding pin is mounted thereon; and Fig. 4 is a view of the step-by-step element when in position for receiving time signals.

In the drawing there is shown a selective signalmg system to which may be connected a very large number of waystations, at each of which is a selector selectively responsivewaystations to the exclusion of all, other stations, and the feature of calling all stations at the same time.

In the drawing, 70 and 71 designate line wires extending from a central transmitting or despatchers station to a plurality of receiving or waystationsgB and C. At each waystation there is a selector 72, comprising a polarized electromagnet the windings 5, 5 of which are connected in bridge of the line wires and in series with a condenser 74 and two impedance coils 75, 75,-and a step-by-step contact carrying element 20 adapted to be advanced step by stepagainst the action of a spring 45in response to succeeding current impulses of opposite polarity through the windings of the polarized electromagnet. Each waystation is also equipped .with a signaling bell 76 under control of the selector thereat and a telephone set 77 included in a normally open bridge of the line wires. A signal battery 78 at each waystation may serve for operating the signal bell 76 and for furnishing current for talking purposes. At each station there may be two additional signaling devices 79 and 80, which may be exactly like the signaling bell 76, controlled by the selector and operated from the local battery 78 thereat. The operating circuit of the signaling bell 76 is closed upon the engagement of the contact arm 21 of the step-bystep element with the contact '22; the operating circuit of the signaling device 80 1s closed when the contact arm 21 engages contact 23; and the operating circuit of the signaling device 79 is closed when the contact arm 21 engages contact 24. Holding pin 29 corresponds to the contact 22, holdto holdthe element in the proper contact ening pin 60 to contact 23 and holding pin 61 -to contact 24. Upon the cessation of the gaging position.

.At the transmitting station A there is a main battery 85 for supplying current foroperating the selectors at the waystations.

" This battery is normally disconnected from the line wires and may be connected therewith by the operation of a relay 86. A pole-changing relay 87 is provided for reversing the connections from battery 85 to the line wires. The relays 86 and 87 are connected in parallel and in circuit with-a local battery 88, and are controlled by the impulse transmitters 89, 90, 91, 92 and 93. The transmitter 89 is for calling waystation B, 90 for calling waystation G, 91 for calling a group of stations, 92 for calling all of the stations, and 93 for preparing the apparatus at all stations for the simultaneous reception of time signals. The transmitters are provided with teeth, certain ones of which may be blocked out by one or both adjustable cams 94 and 95 to obtain the particular numberand combination of effective teeth for calling purposes. Each transmitter is adapted to rotate in the direction of the arrow, and the teeth thereof are adapted to control contact springs 96 and 97 in circuit with the pole-changing relay 87. The free end of contact spring 97 of transmitters 89 and 90 is bent downward, and carries at the extremity thereof an insulating roller 98, which as thetransmitter rotates, is adapted to ride -on top of the cam 95 and separate contacts 96 and 97 during the time of the passage of cam 95.

The contact spring 96 of each transmitter is normally out of engagement with the rotatable disk thereof. During the revolution of the disk of each transmitter, contact spring '96 is in engagement with the disk, maintaining the circuit of relay 86 closed to connect battery 85 tothe line wires and 71. Assuming that transmitter 89 is operated as the disk thereof starts to rotate, the circuit of relay 86 is completed, operating this relay and connecting battery 85 to the line wires. As contact spring 96 rides upon the first tooth, it also engages spring 97 to actuate the pole-changing relay 87 by current from battery 88 to reverse the connection of battery 85 to the line wires. When spring 96 drops between two teeth, relay 87 will be deenergized, and during the time spring 96 is passing over the cam 94, relay 87 will be energized to furnish a prolonged impulse of one polarity, for example, negative. As the disk continues to rotate, alternating impulses are sent over the line, and'when the cam 95 is eas es reached, the insulating roller 98 on spring 97 rides thereon and raises spring 97 to keep it out of reach of spring 96, so that during the time the insulating roller 98 is riding over the cam-95, a prolonged impulse of opto provide a ringing period. When the spring 96 drops onto the cam surface 101, a prolonged positive impulse is sent over the line wires to release the selector at the selected station. When spring 96 is out of engagement with the toothed wheel, relay 86 is released and battery is removed from the I line.

Assuming that the selector at waystation B is arranged to respond to a code of impulses represented by 3--9-3, when the transmitter 89 is operated it will send out the first set of three impulses of alternate polarity. The third impulse is of sufficient duration to permit the magnets of all selectors on the line to release before the first impulse of the second set is sent. It is to be understood that when potential of either polarity is applied to the line for a sufficient interval, the condensers 74, 74 become charged, whereupon the flow of current through the selector magnets ceases and the selector magnets release. Those selectors, including the one at station B, which are arranged to respond to codes of impulses, the first set of which is made up of three impulses, will, in releasing, cause the curved end 38 of the contact springs 35 to engage the holding pin 27 in the contact-carrying member 20, so that the contact-carrying member 20 at these stations will be held in advanced position. All other selectors on the. line, including the one at station C, requiring a different number of current impulses to bring their pins 27, 27 into engagement with the projection 38, will be dropped back to normal position. Nine impulses will next be transmitted over the line to step the ratchet wheel 17 around to'a position where, when the selector magnets are deiinergized, due to theextended duration of the ninth impulse, projection 38 will engage the pin 28 at station B, thus holding the selector thereat in advanced position, while the selector at station C will return to normal position. The selectors at all stations connected to the line, which are arranged to respond to a code of impulses, the sum of the impulses in the first two sets of which totals nine, and those arranged to respond to a code of impulses, the first set of which is of nine impulses, will also be held in advanced pulses now sent over the line circuit will cause the engagement of contact 21 with the contact spring 22 at station B to close an energiz ing circuit for the signaling bell 76, but no other'station on the line will have its contact 21 in engagement with its contact 22.

When the contact arm 21 engages contact 22 at station B and upon the cessation of the last of this set of three impulses, theprojection 38 engages the pin'29 to hold the element 20 of the selector in, contact engaging position. Any one of a'plurality of other signaling devices 79 and 80 at station B may have been operated by a proper number of impulses sent over. the line after the selector thereat had been moved into its secon holding position. I

During the operation of the signaling bell 76 which results from the closure of its energizing circuit a local circuit through the windings of the-selector magnets 5, 5 is intermittently established. This circuit may be traced (referring to Fig. 1) from the upper pole of battery '78, through armature 69, contacts 68 and 67, answer-back resistance 66, windings of the magnets 5, 5, contact spring 35, holding pin 29, and the contact carrying element 20 to'the lower 'pole of the battery 78. The closure of this circuit is of such short duration,,the resistance of the answer-back resistance 66 and the windings of the selector magnets 5, 5 so is possible to equip a line with fifty-five selectors and operate them successfully without interference. With a total number of thirty holes 54, 54 in the contact-carrying member 20, as shown in Fig. 1, it is possible to choose thirty-two as the number of steps required to close the first signaling contact 22, 21 of any selector. This may be done by merely shifting the position of the con-i tact-carrying member 20 on the shaft 18,- so

that the contact 21 is moved farther to the right. If thirty-two be chosen as the number of steps required to close the first sign-aling contact 22, 21 of any selector, there are three hundred and seventy-eight difi'erent combinations possible, and with aselector responsive to each of these combinations, it is possible toequip a line with three hundred and seventy-eight selectors and operate them successfully without interference.

When fifteen is chosen as the number of steps required to close the first si naling contact 22 of any selector, the following Three imbeing obtained by s table represents the different combination or code of impulses for the total number of fifty-five separate stations:

I .It will be seen that the second signaling contact 23 of any selector may be engaged by contact 21 bysending, as the third or last set of impulses, two more than is enumerated in the above table, and the third signaling contact 24 of any selector may be made by sending as the third or. last set of impulsesfour more than is enumerated in this table. a

It will also be seen that if it is desired to select any group of stations (the first signaling contacts thereof) in which the first set 'of impulses is of the same number, for example, the group containing station B, this may be done by sending a code of impulses represented by 312, the second group of twelve impulses being obtained by adding together-the impulses of the second and third sets. In the selecting of a group of stations, only the first removable holding pin 27 is used. The transmitter 91 at the transmitting station A is arranged to send this code of impulses 3-12, and may be used to select this group of waystations, which includes B. Station B may also be included in another roup in which the last set of impulses is of the same number, responsive to a code of impulses represented by 123, the first group of twelve impulses adding together the first two sets of impu es. In this case, only the second removable holding pin 28 will be used.

For the purpose of providing for the simultaneous reception of time signals at all-way stations, the contact carrying mem-' ber or .step-by-step element 20 of each selector is provided with a holding member 55 so positioned that its curved end will be en aged by the curved projectlon 38 of the ho ding spring 35 (as shown in Fig. {1) when the element 20 has been advanced 1n response to twenty impulses of current through the magnet windings 5, 5. -The holding member 55 has a tail piece havlng two lugs 108 and 109, bent at substantially right angles thereto, by means of whlch the holding member 55 is secured to the lower side of the element 20, as clearly shown in Figs. 2 and 3. The curved end of the holding'me mber 55 corresponds to any of the pins 27, 28, 29, 60 and 64 posltloned in the element 20, that is, in sofar as its function of holding the step-by-step element in advanced position is concerned. The tail piece of the holding member 55 is provided so that after the projection 38 of the holding spring 35 engages'the curved end of the holding member 55, the advancement of the element 20 in response to only one or two impulses through the magnet windings 5, 5, followed by the deenergization of the selector magnets, will not permit the return of the element 20 to normal position; for the projection 38 of the holding spring 35 in moving in toward the element 20 will strike thetail piece of the holding member 55 which, due to the action of the spring 45, will be rotated with the element 20 until the curved end of the holding member 55 engages the projection 38. The element 20 will therefore be held in advanced position with the movable contact 21 thereof within one step of the stationary contact 25 or five steps beyond the station contact 22, as shown in Fig. 4:. The length ofthe tail piece of the holding member 55 is such that after the curved end thereof is engaged by the projection 38 the element 20 must be advanced at least four steps more before the projection 38, in moving toward the element 20, will clear the end of the tail piece and permit the spring to return the element 20 to normal position. Contact 25, which may be considered as the time receiving contact, is electrically connected with the station contact 22.

All of the fifty-five stations (the first signaling contacts thereof) may be called simultaneously by sending over the line wires fifteen impulses. It will be seen that neither of the removable holding pins 27 and 28 will be used in calling all stations simultaneously. Transmitter 92 at transmitting station A, as previously mentioned, is arranged to send out a single set of fifteen impulses for calling all stations. All stations may be prepared for receiving time signals over the line wires and 71. For this purpose the transmitting station A is equipped with a transmitter 93, provided with a series of teeth, arranged so thatwhen the transmitter is set in operation an uninterrupted set of twenty impulses of currentof alternate polarity will be transmitted over the line wires. These impulses, in traversing the magnet windings 5, 5, energize the selector magnets causing the advancement of each element 20 to a position where upon the cessation of the twentieth impulse, the deenergization of the selector magnets permits the projection 38 of the holding spring 35 to engage the curved end of the holding member 55, thereby to hold the element in such advanced position. When the projection 38 and the hooked end of the holding member 55 are in engagement, the contact 21 on member 20 is within one step of the contact 25, so that an additional one-step advancement of the ratchet wheel, in response to a single impulse of current through hooked end of holding member 55, and contact 21 will be out of engagement with contact 25. During the time of engagement of contacts 21 and 25, the signaling bells 76 at all stations will be ringing. The one-step advancement of the ratchet wheel at all stations is controlled by a relay 105 located in a separate circuit 106, which may be controlled from the transmitting station or from some oflice located at a distance from the transmitting or despatching station. Preferably, this circuit 1.06 is connected on the standard time wire or telegraph line over which time impulses are sent from the National Observatory at Washington, D. 0. Just prior to the time when the time signalsare to be received, the transmitter 93 is operated to send out twenty current impulses of alternate polarity to step all se lectors' into position where, when the selector magnets are deenergized, the projections 38, 38 engage the hooked ends of the holding members 55, 55,and the contacts 21,- 21 will be one step from the respective contacts 25, 25.

When transmitter 93 has returned t normal position of rest, relays 86 and87 will be deenergized. A switch 107 is now :closed to operate relay 86 to hold current of one polarity on the line. Now, as impulses are sent over the standard time wire to which circuit 106 is connected, relay 105-is energized by each impulse to close its contact and operate the, pole changing relay '87 which in reversing the polarity of current upon the step-by-step contact carrying elements 20, 20 are advanced one step to cause the engagement of contacts 21 and 25 at all way stations. Upon the engagement of the contacts 21 and 25 at each way station, an energizing circuit for the vibrating bell 7 6 thereat is closed to cause the operation thereof. Upon the cessation of the impulse over the line wires, the selector magnets are deenergized and, due to the action of the springs 45, 45, all elements 20, 20 are rotated to cause the disengagement of the contacts 21 and '25 and to cause shortly thereafter the engagement of the hooked ends of the holding members 55, 55 and the projections 38, 38. .The contacts 21, 21 are now held within one stepof the contacts 25, 25. Since the impulse-over the line Wires is of but very short duration,

the contacts 21 and 25 will be in but momentary engagement and the bells will be tapped but once or twice. When the contact of relay 105 is opened, due to the cessation of the impulse over the time circuit, the pole changing relay 87 is denergized, whereupon an impulse of opposite polarity from the sending battery 85 is transmitted over the line wires causing the energization of all selector magnets to again advance the elements 20, 20 and close the contacts 21 and 25 as before. Upon the cessation of this impulse over the line wires, the denergization of the selector magnets causes the disengagement of the contacts 21 and 25 and the return of the elements 20, 20 to the former position Withthe projections 38, 38 engaging the hooked ends of the holding members 55, 55. After the time signals have been received, all selectors may be returned to normal position by opening switch 107 and operating any transmitter, which will send out at least four impulses to move the elongated holding member beyond the point Where it will be engaged by projection 38.

What is claimed is:

1. In a selective signaling system, line wires joining a sending and a plurality of way stations, a plurality of sets of signaling devices, the signaling devices of each .set being at difierent way stations, a selector at each way station controlling in different signaling positions the signaling devices thereat, a polarized electromagnet for each selector connected in bridge of the. line Wires and responsive to constant sized groups of current impulses of opposite polarity, to advance the selectors into the dilferent signaling positions, a source of current, and means at the sending station for transmitting over the line wires each of the several constant sized groups of current impulses of opposite polarity in subgroups of predetermined size for selectivelyoperating the signaling devices.

2. In a selective signaling system, a line circuit, a sending station and a plurality of ,waystations connected therewith, a signaling,

device at each waystation, a selector at each V waystation controlling the signaling device thereat, a polarized electromagnet for each,

selector connected with the line circuit and responsive to a constant sized group of succeeding current impulses of opposite polarity for advancing the selectors into predetermined positions, over the line circuit the comstant sized groups of current impulses of opposite polarity in subgroups of predetermined sizes for selectively operating the signaling devices by groups,

3., In a selective signaling system line wires, a sending station and a plurality of waystations connected therewith, a signaling device at each waystation, a selector at each waystation controlling the signaling device thereat, a polarized electromagnet for each selector in bridge of the line Wires and responsive to a constant number of alternatinq' current impulses for advancing these rent, means at the sending station for selectively calling any waystation and also for controlling the advancement of all selectors to a predetermined position, a telegraph line, and means actuated by impulses impressed upon the telegraph line to transmit over the line wires a succession of impulses from said source, the selectors at all waystations advancing one step to momentarily operate the signaling devices in response to each impulse over the line Wires.

5. In a selective signaling system, line wires, a sending station and a plurality of waystations connected therewith, a step-bystep selector at each waystation having an electromagnet responsive to current impulses, a signaling device controlled by each selector, a source of current, means at the sending station for transmitting current impulses over the line wires to selectively operate a signaling device and also for advancing the selectors. at all waystations to a predetermined position, a telegraph line, and means actuated by impulses impressed upon the telegraph line for transmitting an impulse of current from said source over the line Wires to cause a one-step advancement of the selectors at all stations from the predetermined position to operate the signaling devices each time an impulse is impressed on the telegraph line.

6. In a selective signaling system, in combination, line wires having a sending station and a plurality of waystations connected therewith, an electromagnetic step-by-step selector at each waystation responsive to current impulses, means at the sending station for advancing anyselector into a first predetermined positionand also for simultaneously advancing all selectors into a second predetermined position, a, signaling device at each waystation operated by the advancement of the selector thereat into its first predetermined position, means at the sending station for causing successively the simultaneous one-step advancement of all selectors from the second predetermined position, and means controlled by each such one-step advancement of the selectors for operating all signaling devices.

7. In a selective signaling system, line Wires, a sending station and a plurality of waystations connected therewith, a step-bystep selector at each waystation having an electromagnet responsive to current impulses, a signaling device controlled by each selector, means at the sending station for transmitting current impulses over the line Wires to selectively operate a signaling device and also for simultaneously advancing the selectors at all waystations to a predetermined position, means at the sending station for causing successively the simultaneously one-step advancement of all selectors from the predetermined position, and means controlled by each such one stepadvancement of the selectors for operating all signaling devices.

8. In a selective signaling system, in combination, line wires having a sending station and a plurality of Waystations connected therewith, an electromagnetic, step-by-step selector at each waystation responsive to sueceeding current impulses of opposite polarity, a source of current, means at the sending station for transmitting over the line wires succeeding impulses of opposite polarity from the source of current for advancing any selector into a first predetermined position and also for simultaneously advancing all selectors into a second predetermined position, a signaling device at each waystation operated by the advancement of the selector thereat into its first predetermined position, means at the sending station for causing successively the simultaneously one-step advancement of all selectors from the second predetermined position and means controlled by each such one-step advancement of the selectors for operating all signaling devices.

mitting over the line wires succeeding impulses of opposite polarity from the source of current for advancing any selector into a first predetermined position and also for simultaneously advancing'all selectors into a second predetermined position, a telegraph line, and means actuated by impulses .im-

pressed upon the telegraph line for transmitting an impulse of current from said source over the line wires'to cause a one-step, advancement. of the selectors at all stations from the second predegermined position to operate the signaling evices each time an impulse is impressed onthe telegraph line.

10. In a selective signaling system, a line circuit, a sending stationand a plurality of waystations connected therewith, a. plurality ofsets of signaling devices, the signaling devices of each set being at different waystations, a selector at each Waystation controlling in different signaling positions the signaling devices thereat a polarized electromagnet for each selector connected with the line circuit and responsive to constant sized groups of succeeding current impulses of opposite polarity for advancing the selectors into different signaling positions, a

source of current, and means at thesending station for transmitting over the line circuit from the source of current any one ofthe several constant sized groups of succeeding impulses of opposite polarity in predetermined subgroups for selectively operating the signaling'devices.

In Witness whereof. I hereunto subscribe my name this 20th day of April A. D1917. JOSEPH d. FIELD. 

